Why does near vision deteriorate?
The lens is a clear lens inside the eye, suspended by thin ligaments from the ciliary muscle. When we look close, the muscle contracts, the ligaments relax, and the lens becomes convex, increasing refraction. Throughout life, the lens grows and thickens, so the volume of accommodation gradually decreases from adolescence. By about 40–45 years it becomes insufficient for reading at the usual distance. In people with initial farsightedness, complaints appear earlier, and in people who are nearsighted later: sometimes it is enough for them to take off their distance glasses.
- Initial presbyopia - difficulty with small print in the evening
- Advanced - glasses needed for any close work
- Combination with myopia - remove glasses when reading
- Combination with farsightedness - it is difficult to see both near and far
- Premature presbyopia—with diabetes and certain medications
Causes and risk factors
The main and inevitable reason is age. Eye exercises, vitamins and supplements do not stop the lens from hardening, although proper eye rest will reduce visual fatigue. Previously, presbyopia appears in people with uncorrected farsightedness, in those who work a lot with small parts, as well as in diabetes mellitus and taking certain medications, such as certain antidepressants and antihistamines. Bad habits, ultraviolet radiation and lens diseases accelerate age-related changes and increase the risk of cataracts.
- Age over 40
- Uncorrected farsightedness
- Diabetes mellitus
- Taking certain medications
- Prolonged close work
- Smoking and excess ultraviolet radiation
Symptoms
The first thing a person notices is the need to move text, phone or price tags to arm’s length. Small print blurs, especially in the evening and in dim lighting, because in the dark the pupil dilates and the depth of field decreases. When reading or working with documents for a long time, fatigue and burning in the eyes, headaches appear, and it is difficult to move your gaze from a distance to a close distance. Gradually, a person begins to need a brighter lamp and larger font on the screen.
- I have to move the text further
- Fuzziness of small font
- Worsening in low light
- Tired eyes and headaches when reading
- Slow focusing when looking away
- Need for bright light
Diagnostics
The ophthalmologist checks distance and near visual acuity, determines refraction using an autorefractometer and selects lens strength for different working distances: reading, computer, distance. It is important to take into account a person’s habits - how much time he spends watching a screen, whether he drives a car, or whether he does handicrafts. At the first visit, all patients over 40 years old are recommended to measure intraocular pressure, examine the lens and fundus of the eye. This allows you not to miss glaucoma, cataracts, diabetic and age-related changes in the retina that go unnoticed.
- Testing distance and near visual acuity
- Autorefractometry
- Selection of correction for different distances
- Measuring intraocular pressure
- Biomicroscopy of the lens
- Fundus examination
Correction and treatment
The easiest way is reading glasses, which are worn only for close work. If a person needs correction at a distance, bifocal lenses or progressive lenses with a smooth transition of zones that require a short period of adaptation are suitable. There are multifocal contact lenses and monovision, when one eye is adjusted to distance and the other to near. Surgical methods - replacing the lens with a multifocal artificial lens and laser techniques - are discussed individually, especially with incipient cataracts. Ready-made glasses without an eye test may not be suitable if the eye strength is different or there is astigmatism.
- Reading glasses
- Bifocal and office lenses
- Progressive lenses
- Multifocal contact lenses
- Monovision
- Replacing the lens with a multifocal lens
- Good lighting and breaks when working close
